1,658 research outputs found
Wound healing suppressant effect of vincristine reversed by vitamin A: an experimental study
Background: Use of antineoplastic drugs pre and postoperatively have shown to adversely affect the healing of surgical wounds. Vincristine is an antineoplastic drug with a wide range of antitumor activity. Prior studies have demonstrated that vincristine impairs skin wound healing.Methods: In this study we investigated the effect of vitamin A on vincristine induced suppression of healing in two wound models, viz: incision and dead space in rats. Hydroxyproline (measure of collagen) was estimated colorimetrically and breaking strength of the wound and granulation tissue was measured.Results: Vincristine (60 mcg/Kg intraperitoneally, on the 3rd wounding day) significantly reduced breaking strength in both incision and dead space wound models. Vitamin A (5000 I.U, Subcutaneously on alternate days) by itself did not alter any of the parameters studied but reversed the suppressant effects of vincristine on wound healing.Conclusions: Vitamin A by itself produced little effect on healing except a modest increase in granulation mass. But it significantly reversed the healing suppressant effects of vincristine
A study of the Space Station Freedom response to the disturbance environment
A relatively general formulation for studying the dynamics and control of an arbitrary spacecraft with interconnected flexible bodies has been developed. This self-contained and comprehensive numerical algorithm using system modes is applicable to a large class of spacecraft configurations of contemporary and future interest. Here, versatility of the approach is demonstrated through the dynamics and control studies aimed at the evolving Space Station Freedom
Indications of repair of radon-induced chromosome damage in human lymphocytes: an adaptive response induced by low doses of X-rays.
Naturally occurring radon is a relatively ubiquitous environmental carcinogen to which large numbers of people can be exposed over their lifetimes. The accumulation of radon in homes, therefore, has led to a large program to determine the effects of the densely ionizing alpha particles that are produced when radon decays. In human lymphocytes, low doses of X-rays can decrease the number of chromatid deletions induced by subsequent high doses of clastogens. This has been attributed to the induction of a repair mechanism by the low-dose exposures. Historically, chromosome aberrations induced by radon have been considered to be relatively irreparable. The present experiments, however, show that if human peripheral blood lymphocytes are irradiated with low doses of X-rays (2 cGy) at 48 hr of culture, before being exposed to radon at 72 hr of culture, the yield of chromatid deletions induced by radon is decreased by a factor of two. Furthermore, the numbers of aberrations per cell do not follow a Poisson distribution but are overdispersed, as might be expected because high-linear energy transfer (high LET) alpha particles have a high relative biological effectiveness compared to low-LET radiations such as X-rays or gamma rays. Pretreatment with a low dose of X-rays decreases the overdispersion and leads to a greater proportion of the cells having no aberrations, or lower numbers of aberrations, than is the case in cells exposed to radon alone.(ABSTRACT TRUNCATED AT 250 WORDS
Content-Adaptive Variable Framerate Encoding Scheme for Green Live Streaming
Adaptive live video streaming applications use a fixed predefined
configuration for the bitrate ladder with constant framerate and encoding
presets in a session. However, selecting optimized framerates and presets for
every bitrate ladder representation can enhance perceptual quality, improve
computational resource allocation, and thus, the streaming energy efficiency.
In particular, low framerates for low-bitrate representations reduce
compression artifacts and decrease encoding energy consumption. In addition, an
optimized preset may lead to improved compression efficiency. To this light,
this paper proposes a Content-adaptive Variable Framerate (CVFR) encoding
scheme, which offers two modes of operation: ecological (ECO) and high-quality
(HQ). CVFR-ECO optimizes for the highest encoding energy savings by predicting
the optimized framerate for each representation in the bitrate ladder. CVFR-HQ
takes it further by predicting each representation's optimized
framerate-encoding preset pair using low-complexity discrete cosine transform
energy-based spatial and temporal features for compression efficiency and
sustainable storage. We demonstrate the advantage of CVFR using the x264
open-source video encoder. The results show that CVFR-ECO yields an average
PSNR and VMAF increase of 0.02 dB and 2.50 points, respectively, for the same
bitrate, compared to the fastest preset highest framerate encoding. CVFR-ECO
also yields an average encoding and storage energy consumption reduction of
34.54% and 76.24%, considering a just noticeable difference (JND) of six VMAF
points. In comparison, CVFR-HQ yields an average increase in PSNR and VMAF of
2.43 dB and 10.14 points, respectively, for the same bitrate. Finally, CVFR-HQ
resulted in an average reduction in storage energy consumption of 83.18%,
considering a JND of six VMAF points
Pattern of drug use in psoriasis inpatients in the department of dermatology at a tertiary care teaching hospital
Background: The pattern of drug use in people hospitalized with a primary diagnosis of psoriasis has never been studied previously in India. The aim of the study was to characterize the prescription pattern of people admitted to hospital with psoriasis so that rational prescribing could be promoted among dermatologists.Methods: Case files belonging to 32 patients, admitted in the Department of Dermatology with psoriasis, of a tertiary care teaching hospital in Kerala, over a period of 1-year were retrieved with the assistance of the medical records department. The data thus obtained was analyzed using descriptive statistics.Results: The average age of patients who were admitted with psoriasis was 49.9 years, and their average duration of hospital stay was 7.96 days. A total of 296 formulations were prescribed to 32 patients. Out of 296 formulations, only 10 (3.37%) were generic and rest 286 (96.62%) branded. Fixed dose combinations consisted of 32.43% (96/296) of the prescribed formulations. Psoriasis vulgaris (56.25%) was the most common cause for admission. Of all the prescribed medications, 4 (1.35%) did not contain clear instructions for the route of administration. Strength was clearly mentioned in only 89 (30%) of the preparations. In 98% of the prescriptions, the exact dose was missing.Conclusions: The study reveals various deficiencies which exist in the prescribing pattern of drugs for management of psoriasis. Educational interventions among the doctors as well as students should be carried out to promote rational drug use.
Immune Dysregulation in Patients Persistently Infected with Human Papillomaviruses 6 and 11
Human Papillomaviruses (HPVs) 6 and 11 are part of a large family of small DNA viruses, some of which are commensal. Although much of the population can contain or clear infection with these viruses, there is a subset of individuals who develop persistent infection that can cause significant morbidity and on occasion mortality. Depending on the site of infection, patients chronically infected with these viruses develop either recurrent, and on occasion, severe genital warts or recurrent respiratory papillomas that can obstruct the upper airway. The HPV-induced diseases described are likely the result of a complex and localized immune suppressive milieu that is characteristic of patients with persistent HPV infection. We review data that documents impaired Langerhans cell responses and maturation, describes the polarized adaptive T-cell immune responses made to these viruses, and the expression of class select II MHC and KIR genes that associate with severe HPV6 and 11 induced disease. Finally, we review evidence that documents the polarization of functional TH2 and T-regulatory T-cells in tissues persistently infected with HPV6 and 11, and we review evidence that there is suppression of natural killer cell function. Together, these altered innate and adaptive immune responses contribute to the cellular and humoral microenvironment that supports HPV 6 and 11-induced disease
Evaluation of the antimicrobial and anticancer properties of the fruits of Synsepalum dulcificum (Sapotaceae)
Purpose: To evaluate the antimicrobial and anticancer activities of the fruit of Synsepalum dulcificum (Sapotaceae) against six bacterial strains and on two different colorectal cancer cell lines, respectively.Methods: The dried fruit of the plant was extracted in a Soxhlet apparatus successively with petroleum ether and ethanol, and concentrated in a rotary evaporator to obtain petroleum ether and ethanol extract, respectively. Phytochemical screening was done on the two extracts. The antimicrobial effects of the extracts against Bacillus subtilis, Staphylococcus aureus, Streptococcus pyogene, Pseudomonas aeruginosa, Klebsiella pneumoniae and Proteus vulgaris were evaluated using agar well diffusiontechnique while the anticancer effect of the ethanol extract was assessed on HCT-116 and primary colon epithelial (PCE) cell lines by MTT assay.Results: The results indicate that the petroleum ether extract of Synsepalum dulcificum fruits exerted stronger antimicrobial activity than the ethanol extract. The ethanol extract also showed significant anticancer activity (p < 0.05). The calculated half-maximal concentration (IC50) of the extract on HCT- 116 cells at 24, 48, and 72 h are 14.99, 8.97, and 8.54 μg/mL, respectively, while the IC50 of the extract on PCE cell lines at 24, 48, and 72 h are 236.25, 206.09, and 196.72 μg/mL, respectively. The extract was more toxic to cancer cells than to normal cells.Conclusion: The results of this study lend some justification for the use of the fruits of Synsepalum dulcificum as an antibacterial and anticancer agent
Deafness–associated connexin 26 gene (GJB2) mutations in Iranian population
Mutations in the GJB2 gene at the DFNB1 locus on chromosome 13q12 are associated with autosomal recessive non syndromic hearing loss (ARNSHL) in
many populations. A single mutation, at position 35 (35delG) accounts for approximately 30-63% of mutations in white populations with a carrier
frequency of 1.5-2.5% in most European, North American and Mediterranean populations. In this study we have investigated the prevalence of the GJB2
gene mutations using direct sequencing in 43 presumed ARNSHL subjects from 34 families in an Iranian population. Eleven different genetic variants
were identified. GJB2-related deafness mutations (35delG, 235delC, W24X, R184P and IVS1+1G>A) were found in 9 of 34 families (26.5%). The 35delG
was the most common mutation found in 5 of 34 families (14.7%). We found one novel variant (–3517G>A) in the upstream region to the gene. The
mutation frequency found in this study is lower than other ethnic groups with European ancestry, but it is indicating that mutation in GJB2 in Iranian
population has contribution to ARNSHL. We have also developed a simple and accurate nested PCR assay to screen the 35delG mutation in 250 unrelated
unaffected Iranian individual (controls). No 35delG heterozygous was found in the control population
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